Embodiments of the present invention relate to the treatment and evaluation of a substrate processing chamber.
In the fabrication of substrates, such as integrated circuits and flat panel displays, the substrates are processed in a chamber using energized gases. The substrates are typically made of semiconductor, dielectric or conductor materials. Layers of such materials may also be deposited or otherwise formed on a substrate, by chemical vapor deposition (CVD), physical vapor deposition, ion implantation, oxidation or nitridation processes. Thereafter, the substrate or its overlying layers may be etched in suitable etching processes, to form features shaped as cavities, channels or trenches, in the substrates.
In the processing of substrates, a series of substrates in a batch, such as substrates contained in a cassette holder in a load lock chamber, may be individually selected and transported into a process chamber for processing. Although the same process is performed for all the substrates in the series, the first few substrates may often be processed slightly differently than the other substrates in the same series, even though the process conditions maintained in the chamber are the same. The processing differences may be, for example, differences in etching or deposition rates, differences in etching selectivity ratios, or differences in properties of the etched features, such as their critical dimensions. Processing variations between substrates in a series are undesirable because they reduce substrate yields or processing predictability.
Processing variations such as the xe2x80x9cfirst wafer effect,xe2x80x9d often occur when the chamber has been idle for sometime, in-between the processing of different lots of substrates, or when different types of processes have been performed in the chamber. It is believed that such processing variations often arise due to differences in the processing environment in the chamber that occurs during processing of the first few substrates and the subsequently processed substrates. The processing environment may be different due to differences in the surface chemistry of the internal chamber surfaces. For example, when process residues are formed on the chamber surfaces, the composition of the process residues may affect the partial pressures of the gaseous species in the chamber as a result of chemical equilibrium between the gaseous species and the process residue. The partial pressure of gaseous species in the chamber, in turn, affect the processing characteristics of the substrates being processed in the chamber. For example, in etching processes, variations in the internal chamber environment between one substrate and another, can result in variations of the critical dimensions of etched features between the first few and subsequently processed substrates.
The substrate to substrate processing variations may be reduced by xe2x80x9cseasoningxe2x80x9d the chamber before processing of production substrates. In one seasoning process, a number of seasoning or dummy substrates, such as bare silicon substrates, are processed in the chamber until the chamber yields consistent processing results. Consistent processing results may occur after a few or a large number of dummy substrates are processed in the chamber. Thus, the seasoning process is typically optimized by empirical tests to determine the number of substrates that need to be processed in the chamber to yield consistent processing characteristics. However, these empirical tests are laborious and need to be reevaluated each time any process parameter is changed.
Thus, it is desirable to process substrates with uniform and consistent processing results. It is also desirable to evaluate the condition of a chamber before processing production substrates in the chamber. It is further desirable to season a chamber to provide consistent processing results for a series of substrates in a lot. It is further desirable to reduce the need for empirical seasoning measurements and processes.
A substrate processing apparatus comprising: a chamber comprising a substrate support to support a substrate, a gas supply to provide a gas into the chamber, a gas energizer to energize the gas, and an exhaust to exhaust the gas; a substrate transport to transport a substrate onto the substrate support in the chamber; a detector adapted to detect a first intensity of a first wavelength of a radiation emission from the energized gas in the chamber and generate a first signal in relation to the first intensity and detect a second intensity of a second wavelength of the radiation emission and generate a second signal in relation to the second intensity; and a controller adapted to (i) receive the first and second signals from the detector, (ii) perform a mathematical operation on the first and second signals to determine a value related to a condition of the chamber, and (iii) treat the chamber in relation to the value by providing instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer and exhaust.
A method of treating a substrate processing chamber, the method comprising: (a) providing an energized gas in the chamber; (b) detecting a first intensity of a first wavelength of a radiation emission from the energized gas and generating a first signal in relation to the first intensity; (c) detecting a second intensity of a second wavelength of the radiation emission and generating a second signal in relation to the second intensity; (d) performing a mathematical operation on the first and second signals to determine a value related to a condition of the chamber; and (e) treating the chamber in relation to the value.
A substrate processing apparatus comprising: a chamber comprising a substrate support to support a substrate, a gas supply to provide a gas into the chamber, a gas energizer to energize the gas, and an exhaust to exhaust the gas; a substrate transport to transport a substrate onto the substrate support in the chamber; a detector adapted to detect a first intensity of a first wavelength of a radiation emission from the energized gas in the chamber and generate a first signal in relation to the first intensity and detect a second intensity of a second wavelength of the radiation emission and generate a second signal in relation to the second intensity; and a controller adapted to (i) determine a chamber condition by receiving the first and second signals from the detector and performing a mathematical operation on the first and second signals to determine a value related to a ratio of the first and second signals, (ii) treat the chamber until the value falls within a range of predetermined values by providing first instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer, and exhaust, and (iii) etch one or more substrates in the chamber by providing second instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer, and exhaust.
A method of processing a substrate in a chamber, the method comprising: (a) in a chamber evaluation stage, detecting a first intensity of a first wavelength of a radiation emission from an energized gas in a chamber and generating a first signal in relation to the first intensity and detecting a second intensity of a second wavelength of the radiation emission and generating a second signal in relation to the second intensity and performing a mathematical operation on the first and second signals to determine a value related to a ratio of the first intensity to the second intensity; (b) in a chamber treatment stage, treating the chamber until the evaluated value is within a range of predetermined values; and (c) in a substrate etching stage, providing a substrate in the chamber, introducing a gas into the chamber, energizing the gas, and exhausting the gas.
A substrate processing apparatus comprising: a chamber comprising a substrate support to support a substrate, a gas supply to provide a gas into the chamber, a gas energizer to energize the gas, and an exhaust to exhaust the gas; a substrate transport to transport a substrate onto the substrate support in the chamber; a detector adapted to detect a first intensity of a first wavelength of a radiation emission from energized carbon containing species in the chamber and generate a signal in relation to the first intensity and detect a second intensity of a second wavelength of a radiation emission from energized silicon containing species in the chamber and generate a second signal in relation to the second intensity; and a controller adapted to provide instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer, and exhaust, to: (i) determine a chamber condition by receiving the first and second signals from the detector and performing a mathematical operation to determine a value related to a ratio of the first intensity to the second intensity, (ii) treat the chamber until the evaluated value falls within a range of predetermined values by providing first instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer, and exhaust, to transport one or more first substrates comprising carbon species or silicon species into the chamber, introduce gas into the chamber, energize the gas, and exhaust the gas, and (ii) etch one or more second substrates in the chamber by providing second instructions to operate one or more of the substrate transport, substrate support, gas supply, gas energizer, and exhaust.
A method of processing a substrate in a chamber, the method comprising: (a) in a chamber evaluation stage, detecting a first intensity of a first wavelength of a radiation emission from energized carbon containing species in the chamber and generating a first signal in relation to the first intensity and detecting a second intensity of a second wavelength of radiation emissions from energized silicon containing species in the chamber and generating a second signal in relation to the second intensity and performing a mathematical operation to determine a value related to a ratio of the first intensity to the second intensity; (b) in a chamber treatment stage, treating the chamber until the evaluated value is within a range of predetermined values by providing one or more first substrates comprising carbon containing species or silicon containing species in the chamber, introducing a gas into the chamber, energizing the gas, and exhausting the gas; and (c) in a substrate etching stage, providing one or more second substrates in the chamber, introducing a gas into the chamber, energizing the gas, and exhausting the gas.